This invention is in the field of apparatus useful for making fibrous composites; more particularly, the invention relates to an apparatus and method useful to make coated unidirectional fibrous webs.
Thermosetting and thermoplastic fibrous reinforced sheets and method of making them are known in the art. U.S. Pat. No. 4,362,585 discloses fiber reinforced plastics and an apparatus and methods to make them. A uniaxial oriented nylon film is used as a carrier web or top web for fiber reinforced plastics. At column 5 beginning at line 11 an embodiment is disclosed where only a top film is used. It is disclosed that under certain conditions resin and fiber are fed onto a carrier means such as a conveyor belt or carrier web other than uniaxial drawing nylon film.
U.S. Pat. No. 4,486,172 discloses an oven and method for heating thermoplastic articles. The articles are fed into the oven on a conveyor belt to uniformly heat the article.
U.S. Ser. No. 081,074 disclosed layers made from multi-filament yarn impregnated or coated with a matrix resin. The process is generally disclosed as comprising the steps of bringing the yarn in sheet form onto a carrier web and bringing the yarn laid in unidirectional sheet form into contact with the matrix resin. The matrix resin can be in the form of solution, emulsion or melt. The next step is to consolidate the resin impregnated sheet. This can be accomplished by drying to remove solvent or cooling to solidify the melt. The prepreg sheet is then rolled up and cut for use. In the apparatus and method disclosed the unidirectionally laid yarn is supported by a continuous carrier web through the steps of impregnating with resin and heating in a drying oven. The carrier webs used had to be strong enough to withstand the high tension needed to be pulled through the prepreg process. Typically, the carrier web was made of high strength silicone paper, which is very costly.